What is the maximum column load in kips that could be placed on a $4-$ft square temporary footing on a sand for which the standard penetration resistance is about $N_{60}=15$ and the water table is at the surface? A factor of safety of $2$ is to be maintained against bearing failure.

Solve Problem $3$ if settlement of the footing must be limited to $\frac{1}{2}$ in$.$